A genuinely well done exorcism movie. I love that the demon is rarely seen on screen. There is a lot of shutting doors and lights going off or cameras flashing, all hinting at the spirits presence, without actually revealing it. This, in my opinion, enhances the creepiness and anxiety in the viewer; for indeed, horror lurks in the unknown.
« Fear is defined as the feeling of agitation and anxiety caused by the presence or imminence of danger. »